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Macroscopic polarization and band offsets at nitride heterojunctions

Fabio Bernardini·Vincenzo Fiorentini
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Abstract

Ab initio electronic structure studies of prototypical polar interfaces of wurtzite III-V nitrides show that large uniform electric fields exist in epitaxial nitride overlayers, due to the discontinuity across the interface of the macroscopic polarization of the constituent materials. Polarization fields forbid a standard evaluation of band offsets and formation energies: using new techniques, we find a large forward-backward asymmetry of the offset (0.2 eV for AlN/GaN (0001), 0.85 eV for GaN/AlN (0001)), and tiny interface formation energies.

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Fabio Bernardini, Vincenzo Fiorentini. 1997-12-19. Macroscopic polarization and band offsets at nitride heterojunctions. https://doi.org/10.1103/physrevb.57.r9427

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